Known in the prior art are conveyor belts with articulated links, where the link comprises a main supporting member made of a rigid plastic material, in particular acetalic resin, polyamide or the like, and a secondary member, or insert, preferably made of an elastic or elastomeric material, which has an external upper surface for supporting the product to be conveyed and which is received in a respective socket in the main supporting member of the link.
In prior art conveyors, the secondary or product supporting member is held to the main link supporting member by respective fastening means, which are located on the secondary member and on the main link supporting member and which are in the form of corresponding perpendicular protrusions which fit into matching sockets, with perpendicular walls, formed in the main supporting member.
Disadvantageously, however, in links of this kind, referred to as rubberized, the secondary or product engagement member tends to become detached from the main link supporting member.
This problem is particularly serious when the conveyor is used for transporting certain products, in particular products which are thin and stiff, which tend to get caught under the secondary product engagement member, creating leverage which prises it off the main link supporting member. For example, in the pharmaceutical industry, the blister pack which contains the pharmaceutical and which is normally a stiff plate of layered plastic, easily finds its way between the rubberized secondary member and the main link supporting member, which is made of a rigid plastic material, causing the secondary member to become detached.
In practice, the perpendicular protrusions of the prior art, which extend perpendicularly from the underside of the insert, or secondary product engagement member, are not effective enough in holding the secondary or product engagement member to the main link member.
To overcome this problem, a layer of adhesive has been applied between the underside of the inserts or supporting members of elastomeric material and the corresponding surface of the rigid supporting member. The results, however, have been unsatisfactory especially because of the low durability of the adhesiveness between the link members.
Moreover, up to the present, the protrusions, extending perpendicularly from the secondary or product engagement member and fitting into matching perpendicular sockets in the main link, have been formed by a process whereby the main link supporting member is made of a respective rigid material, such as acetalic resin, polyamide or the like, in a corresponding mould provided with perpendicular cavities, and the elastomeric insert then moulded directly onto the main link supporting member, thus forming the perpendicular fastening protrusions inside the perpendicular sockets formed in the main link supporting member.